The following are some common sense of high-frequency electromagnetic interference filter. For high-frequency electromagnetic interference (), generally three technologies can be used for power filtering to suppress interference noise. In actual use, two or even multiple technologies are often used in combination. They are: 1. Add a capacitor between the hot wire and the neutral wire of the power supply, that is, the X capacitor. The X2 type is , the main function is to common mode interference, and the capacity range is 0.01UF---0.47UF. 2. Add a capacitor between the power line and the ground line, that is, the Y capacitor. Choose Y2 type, mainly to serial touch interference, and the capacity range is 2200pF~0.1μF. In order to reduce the leakage current, the capacitance must not exceed 0.1μF, and this circuit board uses 0.01UF. 3. Common-mode suppression, common-mode inductance (suppression coils on two power lines), when the rated current is large, the wire diameter of the common-mode should be increased accordingly, so that it can withstand large currents. In addition, increasing the inductance properly can improve the low-frequency attenuation characteristics. This circuit uses 10MH. Material: ABS colour: As shown Package Contents: 1 x Filter module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. The input GND needs to be connected to the ground wire of the power line, and at the same time, it can be connected to the chassis shell. Please pay attention to the direction when soldering the 4A common mode inductor. Please install and solder according to the marking on the circuit board and the baby picture. This module is used with a decoder or a power amplifier. It can filter the high-frequency noise of the power supply, the interference of the mains power supply, and purify the power supply. It can obviously improve the sound quality of the power amplifier, increase the resolution and make the background quiet.